Two different games:

All you would really ever want to know about the .17 HMR
http://www.chuckhawks.com/compared_17HMR_22WMR.htm

Some good info about the .17 m2
http://www.chuckhawks.com/17_M2.htm


Note there is a new bullet that weighs 20 grains v. 17 which sort of ups the ante so to speak. The M2 is a short to medium distance hunter where as the .17 is a short to long range hunter (as far as rimfires go), the .22 Mag being king of the game and the .22Lr having better energy for the long haul but a useless trajectory out past 75-100 yards.

CQB ARMS